What are some more modern innovations/inventions in history?

I want to do a National History Day project next year, and the theme is the innovation in history. I've been going through all the Y!A questions about this topic, but all of the things people are suggesting are really old, and I need to use a lot of primary sources for the project. Like, what primary source are you going to use for the printing press? So what are some innovations or inventions that are more modern? My mother and I already have some ideas, but I want more. Thanks!